High Frequency (HF) communications is widely utilised in military, safety and amateur radio systems. Utilising HF communication channels for TCP/IP is highly constrained due to the characteristics of the channel which are presented as low link reliability, limited bandwidth and high transmission delays. Low link reliability is the effect of error prone behavior of HF channels which are governed by physics and environmental conditions. Various implementations of Wideband HF (WBHF) provide additional bandwidth but the low reliability still pose a challenge for TCP/IP communications.
In this paper, we present a novel TCP named HF-TCP which is an enhanced version of the standard TCP to provide better performance on HF communication channels. HF-TCP modifies key parameters of TCP to allow TCP sessions to remain open over an extended period of time while the low-data is transmitted with induced delays. Results from experiments show improvements in transmission success rate of 24 percent over standard TCP which failed to initiate or maintain communication. The proposed HF-TCP is backward compatible with generic Local Area Networks (LAN) and wide Area Networks (WAN).